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Biomedical subjects

M Cormier

Publications and source records attributed to M Cormier.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Implantation of Escherichia coli in pilot experiments and the influence of competition on the flora].

Implantation in seawater and (or) sediment of bacterial flora and the influence of such flora upon the survival and growth of an Escherichia coli of human origin have been the object of experimental pilot studies. The selected pilot plant permitted work on large volumes of seawater and sediment, and maintenance of the structure of the latter. Diverse experiments were carried out in the presence or absence of seawater and (or) sediment bacterial flora during 13 days. Escherichia coli bacteria were introduced in the seawater experimental system at concentrations of 1 to 3 X 10(5) colony-forming units (cfu) per 100 mL. In sterile sediment, E. coli bacteria first went through a proliferative phase and then implanted themselves (3 X 10(4) cfu/100 g at 0 days and 4 X 10(5) cfu/100 g at 13 days). Diffusion in the supernatant sterile seawater of organic matter released from sediment allowed the strain to proliferate (8 X 10(6) cfu/100 mL at 1 day) and survive for a few days (1 X 10(4) cfu/100 mL at 6 days), prior to an ultimate decreasing phase (1 cfu/100 mL at 13 days). In the presence of the seawater indigenous flora, an immediate decrease (2 X 10(3) cfu/100 mL at 6 days), without a growth or even a survival phase, evidenced a selection pressure. In a nonsterile sediment, in the presence or absence of seawater indigenous flora, E. coli bacteria implanted themselves quickly (5 X 10(4) cfu/100 g at 1 day) and survived (1 X 10(4) cfu/100 g at 13 days). In the supernatant seawater, a decrease was observed from the 1st day.(ABSTRACT TRUNCATED AT 250 WORDS)

Escherichia coli↗
PubMed1990

Evidence that Escherichia coli accumulates glycine betaine from marine sediments.

Escherichia coli grew faster in autoclaved marine sediment than in seawater alone. When E. coli was cultivated in sediment diluted with minimal medium M63 at 0.6 M NaCl, supplemented or not supplemented with glucose or with seawater, the osmoprotector glycine betaine was accumulated in the cells. The best growth occurred on glucose. Accumulation of glycine betaine was not observed with E. coli was grown in sterile seawater alone. The fact that E. coli grew better in the sediments than in seawater is attributed somewhat to the high content of organic matter in the sediment but mainly to the accumulation of glycine betaine. Thus, osmoprotection should be considered to be an additional factor in bacterial survival in estuarine sediments.

Betaine↗
PubMed1990

Fluorescent-antibody method useful for detecting viable but nonculturable Salmonella spp. in chlorinated wastewater.

An indirect fluorescent-antibody (IFA) technique, which employed adsorbed Behring polyvalent I O antiserum, was used to detect Salmonella spp. in environmental water systems. The IFA method used in this study detected 95% of Salmonella serotypes encountered in human infections in France, with a sensitivity threshold of 7.5 x 10(3) bacteria per ml of wastewater. Specificity was assessed by testing IFA against Salmonella-free seawater and a variety of bacteria other than Salmonella spp. When used to examine raw and chlorinated wastewater over a 2-month period, the IFA method was successful in detecting Salmonella spp. in all 12 of the samples examined, with total numbers determined to be 4.5 x 10(5) to 3.3 x 10(7) salmonellae per 100 ml. In comparison, for the same samples, enumeration by culture, using the most-probable-number technique, was effective in detecting Salmonella spp. in only four of eight raw-water samples and one of four chlorinated water samples tested. Three samples were further tested by using the direct viable count procedure combined with IFA and results showed that 5 to 31.5% of the Salmonella spp. enumerated by this method in chlorinated water were substrate responsive.

Acridine Orange↗
PubMed1990

Comparative study of gentamicin release from normal and low viscosity acrylic bone cement.

The pharmacokinetics of gentamicin were studied after total hip joint arthroplasties in 2 groups of 10 patients. The prosthesis was performed in the first group with 'Palacos R plus gentamicin' (normal viscosity), manufactured by Schering, and in the second group with 'Cerafix genta R' (low viscosity) manufactured by Ceraver-Osteal. Both cements included similar concentrations of gentamicin. Urine was collected at 12-hour intervals for 15 days after operation, and drainage fluids for 48, 72 or 108 hours. Blood samples were taken 3 and/or 5 hours after prosthesis implantation. In both cases, high concentrations of gentamicin were found in drainage fluids and urine during the early postoperative period. Mean gentamicin excretion curves were calculated by a computer-aided design program (SIAM) for the 2 cements. The release of gentamicin was biphasic in both cases, although the slow elimination phase appeared to be longer for 'Cerafix'. In the first postoperative period, the drug had a better bioavailability during the rapid elimination phase in the case of 'Palacos'. The calculated peak blood concentration was in the same range for both compounds. The conclusion is drawn that, in patients undergoing total hip joint arthroplasties, gentamicin concentrations reach local levels higher than the minimum inhibitory concentrations of most of the likely sensitive pathogens. However, in both cases, as blood concentrations appear to be low, patients will not be protected against systemic infections. Both cements have similar antibacterial properties but the mechanical properties of 'Cerafix' are the better of the two.

Adult↗
PubMed1990

[A comparison of culture and immunofluorescence technics in the study of Bacteroides with black pigmentation].

The aim of that study was to compare culture and immunofluorescence (IF) methods to determine whether B. gingivalis and other B.P.B. can be detected in subgingival plaque of children. Samples were collected from the lingual sulcus of mandibular incisors, dispersed and diluted from 1 to 10(-5); 15 microliters of each dilution were plated on Trypticase soja agar and Todd-Hewitt agar supplemented with blood, Vit K 1 and hemin. The same dilutions were smeared on glass slides for indirect IF using an species-specific polyclonal rabbit whole cell antiserum to B. gingivalis ATCC 33 277. Representative colonies producing brown-to-black pigment were isolated, purified and further characterized. Using culture, BPB were detected in 46% of children (19/41). B. gingivalis was cultured from 6 children. Using immunofluorescence test (Fluotec*), 90% of 309 children 3 years old and more harbour detectable B.P.B., but B. gingivalis don't react with that test. B. gingivalis were detected by immunofluorescence in 72% of children (30/41) in the incisor plaque.

Adolescent↗
PubMed1990

Susceptibilities of coagulase-negative staphylococci to aminoglycosides antibiotics as compared by early bactericidy assays.

Twenty four strains of coagulase-negative staphylococci from clinically significant blood cultures were separated in four groups on the basis of oxacillin susceptibility and phenotype of resistance to aminoglycoside antibiotics. Susceptibility testing included disk diffusion testing, M.I.C. and M.B.C. determinations and finally, measurements, at sequential times (from 0 to 6 hours), of the bactericidal effect of aminoglycosides alone or combined with oxacillin or vancomycin. Aminoglycosides clinical use (gentamicin, netilmicin, tobramycin and amikacin) exhibited an efficient early bactericidy over the sensitive strains to any tested aminoglycosides and to oxacillin (group 1, 13 strains). When strains having a phenotype of resistance to kanamycin and neomycin (group 2, 4 strains) or kanamycin and tobramycin (group 3, 2 strains) were considered, amikacin inefficiency was assessed by time-killing assay even though disk diffusion testing as well as M.I.C. and M.B.C. determinations failed to demonstrate it. In the same way, only bactericidy measurements indicated the lack of activity of amikacin or netilmicin over strains exhibiting a phenotype of resistance to gentamicin plus kanamycin and tobramycin (group 4, 5 strains). Netilmicin appeared as the most active aminoglycoside over the strains studied. Crude results of disk diffusion testing might appear as an oversimplification, especially when coagulase-negative staphylococci are considered; the early-bactericidy assay findings were stressing for the need of interpreting the results of antibiotic testing on the ground of resistance mechanisms.

Aminoglycosides↗
PubMed1989

Effect of carbonyl cyanide m-chlorophenylhydrazone on Escherichia coli halotolerance.

The growth-inhibitory effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP) was less on members of the family Enterobacteriaceae (halotolerant organisms) than it was on species of Vibrio (moderately halophilic organisms). When sodium chloride concentration increased from 0.5 to 0.85 M, this effect was more pronounced for Escherichia coli; it remained relatively stable for Vibrio spp. The effect of carbonyl cyanide m-chlorophenylhydrazone was antagonized by the addition of glycine betaine or proline or by growth in a rich medium.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗
PubMed1989

Production of 4-methylumbelliferyl heptanoate hydrolase by Escherichia coli exposed to seawater.

The production of an enzyme, 4-methylumbelliferyl heptanoate hydrolase, in Escherichia coli exposed to enriched and nonenriched seawater was studied. In all media, except for seawater with no or very small amounts of organic material and seawater enriched with peptone, 4-methylumbelliferyl heptanoate hydrolase activity increased by 2 to 3 orders of magnitude within 2 days. Increased enzyme activity was assumed to be related to cells not undergoing lysis but adapting to conditions of nutrient limitation.

Colony Count, Microbial↗
PubMed1989

Release of gentamicin from acrylic bone cement.

The pharmacokinetics of gentamicin were studied after total hip joint arthroplasties performed with "Palacos R plus gentamicin' in 10 patients. Urine was collected at 12-hour intervals for 15 days after operation, and drainage fluids for 48, 72 or 108 hours. Blood samples were taken 3 and/or 5 hours after prosthesis implantation. High concentrations of gentamicin were found in drainage fluids. Excretion curves in drainage fluids or urine were fitted by a computer-aided design program (SIAM) and the mean curves established. Elimination of gentamicin was biphasic in both cases. The rapid phases had a half-life of 2.97 hours in drainage fluids and 7.16 hours in urine. Half-lives of the slow phases were 13.5 and 47.12 hours, respectively. The mean percentage of total gentamicin released by the two routes was 5.78% of the quantity implanted. The calculated peak blood concentration was 0.12 mg/L. It is concluded that gentamicin concentrations locally reach levels higher than minimum inhibitory concentrations of most of the likely pathogens in patients undergoing total hip joint arthroplasties with "Palacos R plus gentamicin' bone cement. However, as blood concentrations appear to be low, patients may not be protected against systemic infections.

Adult↗
PubMed1988

Comparative effects of four surfactants on growth, contraction and adhesion of cultured human fibroblasts.

A range of surfactants, including the anionic sodium dodecyl sulfate, the cationic cetyltrimethylammonium bromide and the non-ionics octylphenoxy polyethoxyethanol (Triton X100) and polyoxyethylene 20 sorbitan monoleate (Tween 80) was studied for effects on proliferation, contractibility and attachment of cultured human fibroblasts. Only ionic surfactants exhibited a stimulatory effect on fibroblast proliferation, whereas all the surfactants tested increased the contraction of collagen gels containing fibroblasts, with the greatest effect from the non-ionic surfactants. This activity was not correlated with an increase of cell population or cell attachment within the collagenous matrix. The activity of the surfactants was seen only at levels close to their LD50 values and in a narrow range of concentrations. Thus, we consider that they are the result of the so-called hormesis phenomenon.

Adult↗
PubMed1988

[Infections and utilization of antibiotics in the hospital, results from a prevalence survey in 1986].

To estimate the rate of infectious diseases and the efficiency of medical care in our hospital, we conducted a prevalence survey of both infections and antibiotic use on 588 inpatients. Results showed that 125 patients (21% of the total) had infections; of these, 56 had nosocomial infections. A third of the patients had been receiving antimicrobial drugs; among them, 30% were receiving the drugs for prophylactic reasons. A misuse in the prophylaxis of infections was determined, particularly in the duration of treatment. The study demonstrated that an effective infection-control program and an antibiotic policy are required in our hospital.

Anti-Bacterial Agents↗
PubMed1988

[Antibiotic-loaded orthopedic cements. Pharmacokinetics and bone level].

A mechanical study in the laboratory of 10 types of cement has shown that the characteristics of low viscosity antibiotic-loaded cements are comparable with those of standard cement without antibiotic and of standard viscosity. A study of the release of Gentamycin in 26 patients treated by total hip replacement showed that the concentration of antibiotic in the drainage fluid was much greater than the minimum inhibitory concentration whereas the low blood concentration gave no risk of ototoxicity or nephrotoxicity. This method of administration achieved antibiotic concentrations in the tissues in contact with the prosthesis 10 times greater than those obtained by injection. In sheep, the intra-osseous concentration was studied in 32 femora after insertion of low viscosity Gentamycin-loaded cement. The levels remained raised to 4 times the minimum inhibitory concentration for up to one year after operation, even with cements with a low concentration of antibiotic of 0.6 g/dose. The concentrations obtained in the drainage fluid, in the peri-prosthetic tissues and especially in bone, confirm the effectiveness and the prolonged action of antibiotic therapy by cement and its value in the revision of infected prostheses and in prophylaxis in primary surgery. This justifies the further study of combinations of cement with new antibiotics with a broader spectrum than Gentamycin since there is no concern with the cements currently in use that the mechanical quality is less than that of standard cement.

Animals↗
PubMed1987

Catamenial pneumothorax: case report and literature review.

Since the initial case report in 1958, 69 cases of catamenial pneumothorax have appeared in English-language literature. Despite the extensive case material, the pathogenesis has not been fully elucidated. Herein an additional case is reported utilizing computed tomography (CT) to search for intrathoracic endometrial implants. The four major pathogenetic theories include passage of air from the genital tract via diaphragmatic defects, spontaneous rupture of subpleural blebs, intrathoracic endometriosis, and prostaglandin-induced bronchiolar constriction resulting in alveolar rupture. Evidence for and against each theory is presented.

Adult↗
PubMed1983

Optimal enrichment time for isolation of Vibrio parahaemolyticus from seafood.

The growth of Vibrio parahaemolyticus in a liquid medium was compared with that of human fecal flora and estuarine flora. No marked differences were noted between growth at 25 and 37 degrees C for V. parahaemolyticus. However, the marine organisms were strongly inhibited when incubated at 37 degrees C. Incubation for 8 h in an enrichment broth yielded V. parahaemolyticus growth, even with a small inoculum, whereas the marine and fecal floras were inhibited. Therefore, enrichment for 8 h at 37 degrees C appears to be optimal for isolation of V. parahaemolyticus, permitting more rapid results in seafood analysis.

Animals↗
PubMed1981

[The extemporaneous histological examination of the umbilical cord. A reliable procedure for evaluating the risk of neo-natal infection (author's transl)].

The authors report a study carried out on a consecutive series of 184 placentas of immature or small-for-dates newborn for whom a concomitant examination of the umbilical cord was carried out, with the purpose of finding out whether there was infection of the cord which was defined expressly as a true umbilical blood-vessel infection. The 27 cases of infection which were found were classified using a method with 5 values of 0 to 5 given to two sections of the cord that were sectioned. The one was near the placenta, the other near the fetus. Then the findings were compared with the clinical picture of infection in the infant and with bacteriological tests carried out on the digestive tract and on the meconium. This comparison shows how reliable this examination was in prognosing the risk of neo-natal infection and it would appear in screening out neo-natal infection by adding raised values for infection in the cord.

Bacterial Infections↗